Footer construction



' "Aug. 9, 1938., H. s. CLAYBAUGH' FOOTER CONSTRUCTION Filed March 6, 1937 2 Sheets-Sheet l INVENTOR H WARD 6. C LAYBAU 6H ATTO FYNEYEI 1 H. s. CLAYBAUGH 2,126,091

FOOTER CONSTRUCTION Filed March 6, 1937 2' Sheets-Sheet z INvENTdR HOWARD vS-CLAYBAUGH ATTORNEYS Patented Aug. 9, 1938 UNITED STATES FOOTER CONSTRUCTION Howard S. Claybaugh, Minneapolis, Minn., assignor to Lyle Culvert & Pipe Company, Minneapolis, Minn., a corporation of Minnesota Application March 6, 1937, Serial No. 129,433

8 Claims. (Cl. 61-16) kind, large or small.

Heretofore such footings have generally been constructed of concrete, or expensive material difficult and costly to install.

This invention provides a structure particu larly adapted for that type of bridge or arch composed of corrugated plates, both standard or multiplate construction in which a number of plates can be connected together in lapped relation. By multiple construction is meant heavy gauge material in which the corrugations are wider and deeper.

One of the objects of this invention is to make footers of corrugated metal, with the corrugations extending either crosswise or lengthwise of the footers, and using the corrugated material in a manner to obtain reenforcement or extension and increased area of contact with the earth. Uncorrugated or plain sheets can however be used, and no limitation is intended. The size of the footer depends entirely on the hearing power of the soil, it being of course understood that the diiferent types of soils require different widths or areas of thrust surface, for supporting the load of a given weight of bridge or arch. w

An important feature of the invention is the provision of the outwardly and downwardly facing concave elements as footers, the areas of which can be varied thereby providing thrust surfaces of suitable area. Another feature is the manner of bracing the concave surface-forming elements to prevent flattening under stress.

Features of the invention include all details of construction shown along with the broader ideas of means inherent in the disclosure.

Objects, advantages and features will appear in the description of the drawings forming a part of this application, and in said drawings,

Figure 1 is a sectional elevation showing the device imbedded in the earth and supporting a corrugated metal arch which in turn supports a road flanked by a brick facing;

Figure 2 is a perspective view of one form of my invention showing a corrugated arch element in operative relation thereto; a Figure 3 is a detail cross-section of one of the footers, taken on line 33 of Figure 4;

Figure 4 is a sectional elevation looking from line 4-4 toward the inner side of one of the members and showing the corrugated arch member connected to the abutment iron of the footer;

Figure 5 is a perspective view of a modification in which two corrugated elements are overlapped for reenforcement and for varying the thrust area of the footer;

Figure 6 is a perspective view of the portion of the structure of Figure 5, and

Figure '7 is a diagrammatic view illustrating the relative position of the footer with respect to the resultant line of force of the arch thereon.

Referring first to Figure 1, numeral I indicates a corrugated or other suitable metal arch element in which the long dimension of the corrugations run circumferentially, see Figure 2. This arch supports suitable material of brick, stone or earth work 2 which may represent the road for which the arch is a culvert-forming element. Numeral 3 generally indicates the unit of this invention which includes two transversely spaced arch thrust-sustaining footers. These footers are cross-connected to prevent separation. Referring to Figure 3 each footer is herein shown as composed of two sheets of corrugated steel with the long dimension of the corrugations extending lengthwise of the member. 7 A single sheet may be used and be bent at right angles substantially to form a horizontal portion in and vertical portion II, the sheet as thus bent being so disposed as to provide a downwardly outwardly faced concavity, the total surface area of which is relatively large, and the surface area of which can be varied.

The areas of these surfaces of course depend entirely upon the bearing power of the soil, and will vary with different types of soils and with the amount of load. In this instance the corrugated sheet is placed on and attached to a truss frame composed of a horizontal angle iron 20, a vertical angle iron 2|, the irons being mitered and connected as by welding at 25. They are braced by a diagonal member 22, related to the concave surface, formed by the elements I0, If, as the chord to its arc and designed to resist strains tending to lessen the degree of concavity of the thrust sustaining faces of the footer.

The structure constituted by elementsZEl, 2| and 22 may be considered a bracket and any suitable number of such brackets or trusses may be spaced lengthwise of each footer. For a short footer three is a good number, one placed at each end and one in'the middle; These elements are conveniently constructed of angle iron or may be constructed of channel iron. Numerals 26 indicate rivets securing the metal to the brackets. When greaterarea With more strength is required, two or more corrugated sheets can be nested or lapped and longitudinal extension may be had by lapping the ends of contiguous sheets. This is a valuable feature.

At or near the region of overlap between the portions l0 and H, the structure is flattened as at 28, and this flattened portion slants inwardly and downwardly and is placed to obtain the most advantageous thrust transmission and distribution to the footer.

On this portion 28 is suitably secured an angle iron 29 as an abutment for the foot of the arch. This abutment extends the full length of the footer and is suitably bolted or riveted as indicated at 30. Its concave side faces upwardly and toward its companion of the opposite side, see Figure 2. The resultant of load may be generally represented by the line 3| which lies between the margins 32, 33 of the concave ground engaging thrust surface.

Means is provided for cross-connecting the thrust members to prevent separation and to equalize the load. This means includes angle irons which may have the form of a channel iron. In this instance three irons are used, but it is understood that any number may be used, and the number will be varied to correspond to the number of trusses used. Sets of cross irons and trusses are composed of three elements lying in the same vertical plane. The ends of the irons 40 are connected by suitable fastening devices 4|, 42. The, fastener 4| passes through the abutment iron 29. and the fastener 42 passes through the vertical iron 2|. Braces or struts 45 are arranged at the inner sides of the footer and connect the cross members 40 with the flanges of the elements 2| by means of rivets passing through elements I I. The horizontal dimension of Ill, the vertical dimension of H and the lengths of these elements vary as before stated with the bearing power of the soil and. with the load. The elements ID in this case are shown as separate elements overlapped as at 41 and this is a preferred way of constructing this member rather than by making it in a single piece.

It. has the advantage that the smaller parts are. easier to handle and to ship and to assemble, either in singles or nested pairs, or in end lapped relation. The element extending.

; vertically in the ground prevents undercutting of the bridge at this point and acts as well as a thrust surface and actsfor confining the material. An unusually large thrust area is provided by the concavities. The braces 45 prevent turning of the structure and their flanges as well as the flanges of the elements 4|! resist sinking and displacement. They thus add thrust resisting surface to the device as a whole.

. The arches of course as wellas the footing may vary in size, the arches may have a span of seven or eight feet and may be twenty-five or thirty feet in length. The device of course being constructed to take care of the load but the arrangement of the outer and downwardly faced concave surfaces is an important feature of the invention as is also the use of corrugations and of angle or channel irons for increasing thrust surface and preventing spread displacement etc.

In the form illustrated in Figure 5 the outwardly downwardly faced concaved footersurfaces are providedby curving a corrugated metal element. The corrugations extend circumferentially in this case. The curved elements are lapped; One element is indicated at 50, the other at 5|. Rivets 52 secure the elements. The ends are closed by plates 53, and such plates are used for bracing the elements at points intermediately of their ends. The abutment is indicated at 55, the arch at 56. The arch is riveted as at 51 to the channel iron abutment. The corrugations of 5 the elements 50, 5| are nested and can be slid on one another to vary the thrust area. This is a valuable feature.

The elements 5| and elements 53 together form a hollow box-like construction providing an open side which faces downwardly and outwardly. The construction not only gives a broad area of thrust contact, but serves to confine and compact the material and prevent lateral spreading. This box-like concavity has a relatively large to- 15 tal concave surface area.

The elements 22 in combination act in a similar manner not only to prevent flattening of the structure but to provide a boxing effect whereby to confine and prevent lateral spread of the ma terial.

An important feature is to have each foot of the arch apply its thrust to a hollow or troughlike member having its open side directed outwardly and downwardly.

The invention is therefore broader than the specific construction shown, and may be broadly said to consist of the combination of an arch with footers having outwardly and downwardly concave ground engaging surfaces. The box-like configuration is also important. The use of footers having outwardly and downwardly directed concave faces or recesses, with or without boxlike configuration is believed to be new.

Figure '7 diagrammatically illustrates the relative positions of the footers with respect tothe arch. In this figure, the line aa indicates the resultant line of force imposed upon the footer by the arch and the line b-b represents a plane intersecting the edges of the footer, and which line b--b it will be noted, is substantially at right angles to the line wa.

In Figure '7, X represents the span of the arch and Y, the rise. The inclination of the line H will vary in accordance with changes in the values of X and Y. In other words, if the rise Y is increased in height, without increasing X, the resultant line aa will be of less angle with respect to the vertical. Conversely, as the rise is lowered and the span increased, the line a-a will be disposed at a greater angle with respect to the vertical. It will thus be noted that the footers are always set at an angle, determined by the resultant line of force aa. When thus positioned, they will offer the maximum resistance to spreading and settling of the arch and will readily support the load imposed on the arch without the use of expensive cement work or masonry, now commonly used in structures of this character.

I claim as my invention:

1. A device of the class described comprising, a pair of transversely spaced footers each arched and disposed to provide an outwardly downwardly directed concavity, means related as chords to the concave surface of and respectively connecting the outer marginal portions of each footer in a manner to resist strains tending to lessen the degree of concavity, means cross-connecting the footers to prevent separation under load, each footer having an arch-foot-receiving abutment placed to transmit the thrust to the footer so as to be distributed most advantageously relatively to the concave surface.

2. A device of the class described comprising, a

pair of transversely spaced footers each comprising a sheet of corrugated metal with the corrugations running vlongitudinally, each footer being arched and disposed to provide an outwardly downwardly directed concavity, means related as chords to the concave surface of and respectively connecting the outer marginal portions of each footer in a manner to resist strains tending to lessen the degree of concavity, means cross-connecting the footers to prevent separation under load, each footer having an arch-foot-receiving abutment placed to transmit footer so as to be distributedmostadvantageously relatively to the concave surface.

3. A device of the class described comprising, a pair of transversely spaced footers each comprising two overlapped sheets of corrugated metal with the corrugations running longitudinally, one sheet being vertically disposed and one being horizontally disposed, said sheets cooperating and being disposed to provide an outwardly downwardly directed concavity, means related as chords to the concavity and respectively connecting the marginal portions of each footer in a manner to resist strains tending to lessen the de gree of concavity, means cross-connecting the footers to prevent separation under load, each footer having an arch-foot receiving abutment disposed in the region of the overlap of the sheets to transmit the thrustto the footer so as to be distributed most advantageously relatively to the concave surface.

4.In a device of the class described compris-' ing, a pair of transversely spaced footers each arched to provide an outwardly downwardly directed concavity, irons related as chords to the concave surface of and connecting the marginal portions of each footer in a manner to resist strains tending to lessen the degree of concavity, and irons cross-connecting the footers to prevent separation under load, each footer havingan arch-foot-abutment iron placed to transmit the thrust to the footer so as to be distributed over the concave surface, the chord-forming and crossconnecting irons providing concave sides facing downwardly, and arch-foot abutment irons providing opposingly faced upwardly directed concave sides. a i

5. Ina device of the class described comprising a pair of transversely spaced footers each comprising a sheet of corrugated metal with the corrugations running longitudinally, each member the thrust to the 3 being arched and disposed to provide an outwardly downwardly directed concavity, means related as chords to and respectively connecting the outer marginal portions of each footer in a manner to resist strains tending to lessen the degree of concavity, means cross-connecting the footers to prevent separation under load, each footer having secured thereto about midway between its upper and lower margins a longitudinally extending reenforcing angle iron with the concave side facing inwardly and upwardly and acting as an arch-foot-receiving abutment placed to transmit the thrust to the footer so as to be distributed most advantageously relatively to the concave surface.

6. In a structure of the class described, an arch, a footer for supporting each leg of the arch, said footers being substantially trough-shaped in cross section, and means for securing said footers I to the lower edges of the legs of the arch with their concave sides facing outwardly and downwardly in the general directions of the resultant lines of thrust thereon by the arch, whereby the footers will offer maximum resistance to settling and spreading of the arch.

'7. In a structure of the classdescribed, an arch, a footer secured to the lower edge of each leg of the arch, each footer being trough-shaped in cross section and having a concave load supporting surface facing in the general direction of the resultant line of thrust thereon by the arch, whereby the footers will offer maximum re sistance to settling and spreading of the arch, and means whereby the effective area of the load supporting surfaces of the footers may be varied in accordance with the load to be supported by the arch or the character of which the arch is to be supported.

8. In a structure of the class described, an arch, a footer for supporting each side of the arch, said footers being formed of corrugated sheet metal curved to provide inverted troughike members having the corrugations running crosswise thereof, thereby to strengthen said members against straightening, when subjected to a load, and said footers having means on their the material upon outer convexed surfaces for securing thereto the .said footers by the arch.

HOWARD S. CLAYBAUGH. 

